Raj Kumar Paswan

Raj Kumar Paswan

Backend Software Engineer — Python · Distributed Systems · AWS · GenAI

5+ years designing and owning large-scale distributed systems in Django and FastAPI on AWS. I ship production LLM systems (RAG, LangChain, LangGraph) and consistently drive 40–70% improvements in latency, cost and deployment velocity.

I. Skills

Languages & Frameworks

Python · Django · DRF · FastAPI · Flask · Celery · SQLAlchemy

Distributed Systems

Microservices · Event-Driven · REST / WebSocket · Caching · Message Queues · HLD / LLD

Cloud & DevOps

AWS EC2 · S3 · Lambda · SQS / SNS · RDS · CloudWatch · Terraform · Docker · Kubernetes · CI/CD

Data Stores

PostgreSQL · MySQL · MongoDB · Redis · ElasticSearch

GenAI / LLM

RAG · LangChain · LangGraph · OpenAI Function Calling · Pinecone · Prompt Engineering

II. Experience

Apr 2026 — Present

Gurgaon

Software Engineer — Country Delight (Beejapuri Dairy)

Own backend services and the Django admin platform powering daily operations for one of India's largest D2C dairy brands.
Re-architected high-traffic SQL queries and schemas, cutting report generation and API latency across core dashboards.
Built end-to-end stock and procurement workflows, improving inventory accuracy and reducing manual reconciliation.
Designed delivery-partner systems: onboarding, support, and automated salary/tips payouts at scale.

Jul 2023 — Mar 2026

Noida

Software Engineer — Quokka Labs LLP

Owned architecture of 5+ production microservices (Django/FastAPI on AWS) serving 10,000+ concurrent users at 99.9% uptime.
Cut database load 60% and p95 latency 45% by eliminating N+1 queries and strategic indexing.
Reduced response time 40% with Redis caching and SQS/SNS event-driven decoupling.
Shipped a GPT-4 + LangChain RAG support chatbot automating 5,000+ conversations/month at 90%+ accuracy.
Cut deployment time 70% with Terraform, Docker and standardized CI/CD; mentored 3 engineers.

May 2022 — Nov 2022

Kochi

Software Developer (Python) — TOW Business

Designed REST APIs sustaining 50,000+ daily requests at <100ms latency and 99.95% uptime.
Reduced response times 65% via query refactoring, connection pooling and Redis caching.
Scaled to 100,000+ daily Celery tasks with retry and dead-letter handling.
Implemented OAuth2 and Stripe/Razorpay integrations; cut production bugs 40%.

Dec 2021 — Apr 2022

Pune

Software Developer — FindingPI (Shreyas Technosoft)

Reduced downtime 60% resolving critical production issues across Python services.
Automated health checks for 50+ servers, cutting manual interventions 80%.
Reduced MTTD 75% with CloudWatch + SNS alerting.

Sep 2020 — Aug 2021

Noida

Software Developer — Oasis Technologies

Built an HRM platform with IoT integration processing 10,000+ sensor data points daily.
Developed Django backend for employee management serving 500+ employees.

III. Selected Work

Auto-Trading Platform for NSE/BSE

Real-time automated trading system scanning live markets with 99.5% signal accuracy across 1,000+ daily signals, with low-latency stop-loss and profit-booking algorithms.

FastAPI · Celery · Redis · PostgreSQL · WebSocket

AI-Powered Garden Care Assistant

Serverless AI that generates personalized plant-care schedules by combining GPT function calling with live weather data.

OpenAI Function Calling · OpenWeather · GCP Functions · FastAPI

Energy Usage & CO₂ Emission Tracker

Sustainability platform with CO₂ calculations, eco-scoring and vendor recommendations. Supports 5,000+ users, driving 20–30% energy cost reductions.

Django · PostgreSQL · Celery